Status overview from Joao:
After the Rome workshop, we have some open issues and questions for each chapter
1. Consider robustness of detectors in the design: TPC/silicon/wire chamber
2. TPC: Check IBF studies with x-ray source and clarify performance of TPC at 2 Tesla
3. ECAL: Limitations on the photon resolution; define impact on the detector performance if moving to scintillator strips + SiPM design
4. Muon detector: Consider reducing number of muon detector layers and establish performance criteria for the muon detector
5. MDI: Location of the lumical should be in front of beam pipe bellows
Each group should implement these comments in short time. Also we can leave some of the questions in CDR, and give some preliminary study and expectation.
Then, please check the CDR editor, whether some more manpower need to be added
physics: Jianming Qian
Magnet: Feipeng Ning
TPC:
Huirong summarize the topics in Rome workshop and some further research based on the comments from the workshop.
Joao asked the TPC situation for 2T: Huirong is not quite sure, maybe the resolution can be reduced to 150um and de/dx are getting worse
Joao said we need to quantify the impact. Huirong said he will give some answer in next week.
Based on the comments for the IBF from Rome workshop, Huirong did some research to check the influence for IBF performance. He found that the high rate and lots of ions can make the space charge effect to decrease IBF value. For CEPC, since we didn't use the high rate to test the IBF performance, the related the parameter, such as the gain of single GEM, I_pad and Pion*d, are all very low, which can not result in the space charge effect. Also comparing with the GEM+GEM+MM layout for ALICE TPC, our GEM+MM layout can make clear Photo peak and escape peak, with good electron transmission and good energy resolution.
Next step, they will add this discussion in TPC part. They will also test the high rate of X-ray, to check the IBF performance. The test need two weeks.
At last, Manqi suggested to have some research on de/dx at tpc. Huirong said they will consider the electron transmission with beam test, the dedx resolution can be checked at the same time.
Physics and simulation:
Yaquan summarize the analysis status for CDR. He said it will need 1month to finish the analysis and 2 week for finishing the CDR text
On simulation side, Manqi mainly talked about the comparison of benchmark analysis performance for 240GeV@3T geometry and 250GeV@3.5T geometry, especially discussed the reason for bad photon resolution.
Manqi said that the reason for bad h->gammagamma resolution may be related to ECAL resolution or geometry definition. Without the consideration of cost, increasing the thickness of silicon, or changing to SiPM with more thickness can improve the resolution.
Zhijun commented that the uniformity is more important issue: the good calibration or careful commissioning can improve the uniformity.
All the related study can become a paper.